package vip.zhenzicheng.algorithm.huawei_od;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * 输入一个字符串，统计不同字符的个数
 * 例如：aabbcc -> 3
 *
 * @author zhenzicheng
 * @date 2023-02-25 13:58
 */
public class Hj10 {
  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String input = in.next();
    int count = 0;
    Set<Character> set = new HashSet<>();
    for (char c : input.toCharArray()) {
      if (set.add(c)) {
        count++;
      }
    }
    System.out.println(count);
  }
}
